Although the major goal of the Epidemiology Section is the development of a vaccine against Group (Gp) A rotavirus, it is essential to develop reagents and techniques for study of other groups of rotavirus (B-F) since 2 of these groups, B and C, have been implicated as etiologic agents of diarrheal disease in humans. cDNA libraries of porcine Gp C reference strain Cowden and a human Gp C rotavirus isolate were generated previously and the characterization of these libraries was continued this year. Several partial clones specific for different genomic segments from porcine or human Gp C rotaviruses were selected and the nucleotide sequences determined. The proposed gene coding assigmnents for the porcine and human Gp C VP7, NS34, and VP6 proteins were confirmed during in vitro translation studies using transcripts derived from full-length PCR-generated clones. In addition, cDNA clones generated in our laboratory were developed as radiolabeled probes for epidemiologic studies and should prove important for delineating the role of Gp C rotaviruses in human and animal diarrheal disease.